The demand for high stiffness propylene-based polymers with high melt flow continues to increase as the need for more sophisticated polymers continues to grow. Known are polymer catalyst compositions with a mixture of selectivity control agents (SCAs). Mixed SCAs enable the production of olefin-hased polymers that possess properties contributed from each SCA. However, the use of catalyst compositions with mixed SCAs does not change the highly exothermic nature of the olefin polymerization reaction. The excessive heat generated during polymerization poses a significant risk to the polymerization reactor operability. Excessive heat generation and/or inadequate heat removal can readily disrupt production and/or shut down the reactor.
Desirable would be a catalyst composition for production of high stiffness/high melt flow propylene-based polymers that reduces, or eliminates, the risk of reactor disruption, or shut-down due to excessive heat.